Phlegmacium triumphans

The most useful identifying features of Phlegmacium triumphans are its yellowish, two-toned cap and its distinctly veiled, swollen stipe. The cap spans 5–12 cm across, darker in the center and paler toward the margin.

The stipe stands 7–17 cm high and 1–2.5 cm thick, swollen at the base, white toward the top and yellow below, and carries tan or brown remnants of the veil that once covered the gills. When young, the adnate gills are hidden beneath a cream or white veil and appear cream or lilac; they darken as the spores mature, eventually producing a rusty-colored spore print.

The flesh is cream-colored with a mild taste. Spores are almond-shaped, measuring 10–12.5 by 5.5–7 micrometers.

Phlegmacium triumphans grows under birch trees in autumn, forming a mycorrhizal relationship with Betula. It occurs across Europe and is widespread but local in Asia, with reports also from northeastern North America.

Observation records show a strong concentration of sightings in late summer into autumn, consistent with its known fruiting season beneath birches, though these presence records do not indicate abundance or a complete picture of its range.

Phlegmacium triumphans lacks strong traditional medicinal or ceremonial uses, setting it apart from more widely celebrated fungi. Its main documented use is as food: experienced foragers in Europe have known it as a reliable, if unassuming, edible mushroom.

1. The specific name triumphans comes from Latin, meaning "triumphing," while the genus name Cortinarius derives from cortina, meaning "veil," a reference to the partial veil covering the young gills.
2. Some authorities consider it the same species as Cortinarius crocolitus Quélet.
3. It was classified within the subgenus Phlegmacium of the genus Cortinarius, a group historically distinguished by these veiled, viscid-capped mushrooms.
4. The species carries distinct vernacular names across languages, including "birch webcap" and "yellow girdled webcap" in English and "pavučinec zlatý" in Czech.